\begin{table}[htbp]
\centering
\begin{tabular}{ c c c c c c c c} 
  
 Polynomial Order & Mesh: & 4x4 & 8x8 & 16x16 & 32x32 & 64x64 & Overall Order of Accuracy \\ 
 \hline 
 \multirow{2}{*}{$p = 1$} & $L_2$ error & 1.61e+01 & 8.31e+00 & 3.81e+00 & 1.71e+00 & 7.84e-01 &   \\ 
  
   & $\mathcal{O}(L_2)$ &   & 0.96 & 1.12 & 1.15 & 1.13 & 1.10 \\ 
 \hline 
 \multirow{2}{*}{$p = 2$} & $L_2$ error & 4.05e+00 & 8.16e-01 & 1.90e-01 & 4.54e-02 & 1.11e-02 &   \\ 
  
   & $\mathcal{O}(L_2)$ &   & 2.31 & 2.11 & 2.06 & 2.04 & 2.12 \\ 
 \hline 
 \multirow{2}{*}{$p = 3$} & $L_2$ error & 4.71e-01 & 6.39e-02 & 7.03e-03 & 7.75e-04 & 8.84e-05 &   \\ 
  
   & $\mathcal{O}(L_2)$ &   & 2.88 & 3.18 & 3.18 & 3.13 & 3.11 \\ 
 \hline 
 \multirow{2}{*}{$p = 4$} & $L_2$ error & 1.01e-01 & 4.30e-03 & 2.31e-04 & 1.41e-05 &  &   \\ 
  
   & $\mathcal{O}(L_2)$ &   & 4.56 & 4.22 & 4.04 &  & 4.27 \\ 
 \hline 
 \multirow{2}{*}{$p = 5$} & $L_2$ error & 5.04e-03 & 2.50e-04 & 7.80e-06 &   &   &   \\ 
  
   & $\mathcal{O}(L_2)$ &   & 4.33 & 5.00 &   &   & 4.67 \\ 
 \hline 
 \end{tabular}
\caption{Accuracy of HiFiLES for NS equations with source term in triangular meshes at $t = 1$. $L_2$ error is the $L_2$-norm of the error in the gradient of the energy field:$\frac{\partial}{\partial x_i} (\rho e)$}
\label{table:trisError2} 
 \end{table}
